In order to elucidate the reactivities of different types of lignin-structural units toward ozone, various lignin model compounds were ozonized. The results obtained are summarized as follows: 1) An α-carbonyl type structure is much more stable against ozone than a benzyl alcohol type structure. 2) A guaiacyl nucleus reacts faster with ozone than a vera try 1 one. 3) Biphenyl and phenylcoumaran structures react readily with ozone. However, a biphenyl structure of veratryl nuclei is very stable against ozone. 4) From the results of molecular orbital calculations, Pz orbitals (LUMO) of ozone form bonding orbitals to those (HOMO) of lignin aromatic nucleus at C3 and C4 positions. Furthermore, the squares of LCAO coefficients of C3 and C4 positions are greater than those of other positions in Pz orbital (HOMO) of lignin aromatic nucleus. This suggests that ozone reacts selectively with the lignin aromatic nucleus at C3-C4 position.

Polyurethane (PU) sheets were prepared from fractionated kraft lignin (KL) samples having molecular weights (MW's) of 1420 and 860, polyethylene glycol having a MW of 400 (PEG 400) and diphenylmethane diisocyanate (MDI). KL contents in weight %, in a mixture of KL and PEG 400, were varied from 10 to 50%. The thermal and mechanical properties of PU's were studied by thermogravimetry (TG), differential scanning calorimetry (DSC) and tensile tests. The thermal decomposition temperatures slightly decreased with increasing KL contents. The glass transition temperatures (T-g's) increased, the temperature range of glass transition (Delta T) increased, and the heat capacity difference between the glass and rubbery states at T-g's (Delta Cp) decreased, with increasing KL contents, Tensile properties such as strength at break (sigma), elongation at break (epsilon), and Young's modulus (E) were measured at 25 degrees C. The obtained results were highly dependent on the state, i.e. the glassy state and the rubbery state. The effect of molecular weight of KL on thermal degradation and tensile properties was not prominent. However, T-g's apparently increased with decreasing molecular weights of KL when the same amounts in weight % of KL were introduced into PU molecules.

ワラ類には灰文, とくにシリカ分が多く含まれる。したがって, ワラ類の化学パルプ化, たとえばソーダ蒸解において黒液に抽出した灰分は, 濃縮工程においてスケール生成を起こして回収工程を困難にする。以上の問題に関連して, 本報では稲, 小麦および大麦ワラの灰分組成およびアルカリ蒸解中のシリカの挙動を検討した。以下に, 結果を要約する。(1) ワラ類の水抽出物は多い。シリカ残存量は水抽出後の稲および大麦で元のシリカの約70%であり, 小麦のそれは約40%である。稲ワラを水抽出した後の灰分を構成する元素はSiとCaで, その大部分はSiである。(2) 市販シリカの苛性ソーダに対する溶解度は, 稲ワラのそれに比較して著しく少ない。これは両者のシリカの形態構造の相違に基づく。すなわち, 市販シリカはQuartz型であるが, 稲ワラ・シリカはOpal-CT型またはクリストバーライト型と推定される。(3) ソーダ・サルファイトおよびソーダ・メタノール蒸解したパルプのシリカ分は, ソーダ蒸解のそれよりも多い。これは興味ある結果であり, 今後の検討事項はシリカの多いパルプのシート物性の解明である。

(1) The antibiotic activity of carboxylic acid changes remarkably with the species of micro-organisms. Twenty six carboxylic acids (mainly phenol carboxylic acid) were tested toward four kinds of micro-organisms, namely Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus niger. It is difficult to systemize the activity by the relative position of phenolic hydroxyl and carboxyl groups on aromatic nucleus.There have been identified the alkali degradation products of softwood lignin, namely phydroxybenzoic acid, vanillic acid, protocatechuic acid, syringic acid etc. Comparing the relation between the chemical structure of the above phenol carboxylic acids and the antibiotic activity toward micro-organism, it is summarized that the activity of carboxylic acid ester is higher than that of free carboxylic acid, and methoxyl group brings a considerable reduction in the activity.(2) Lignosulfonate and thiolignin do not give the antibiotic activity. In order to give the activity to industrial lignin, the introduction of phenol carboxylic acid type structure into lignin was tried by the use of alkali fusion method. Within the limit of research, so far, the ethanol soluble fraction from alkali fused lignin shows comparatively high activity, although the activity toward Aspergillus niger was not observed. It should be emphasized here, however, that there is no proof of the formation of phenol carboxylic acid type structure in alkali fused lignin.

Soda lignin from rice straw was sulfomethylated, and the dispersion ability of sulfomethylated lignin was compared with that of commercial softwood lignosulfonate. The results are summarized as follows : (1) Black liquor from soda cooking of rice straw was adjusted to pH 8.2 with aq. sulfurous acid. Same mole of formaldehyde as sodium sulfite formed in black liquor was added, and then dissolved lignin was directly sulfomethylated (SML I). Sulfomethylated black liquor was separated by gel filtration method (SML II : 0.18 S/C6-C3).(2) SML I shows the similar standard dispersion number (SDN), regardless of max. temperature of soda cooking and reaction time of sulfomethylation.SDN of sulfomethylated liquor including SWL I, however, is inferior to that of lignosulfonate. This may be due to the low content of sulfonic acid group and low purity of SML I. In order to utilize straw soda lignin as dispersant, it is necessary to isolate soda lignin from black liquor and to sulfomethylate the isolated soda lignin.(3) The setting time of mortar with SML II show the relatively similar results to that of commercial lignosulfonate. SML I, however, requires a long period of the setting time. The utilization of SML I as the dispersant is impractical in mortar manufacture.(4) The dispersion effect with SML II was compared by the use of various types of additives. Among seventeen additives tested here, citric acid, gluconic acid, glucuronic acid and K, H-glucarate show the excellent SDN. Very high SDN shown by K, H-glucarate is worth noting.

In the previous papers [Mokuzai Gakkaishi, 28, 355 (1982), 29, 164 (1983)] piperidine, diethylamine and triethylamin were observed to accelerate delignification at a charge of 1% on wood. Furthermore, the behavior of lignin model compound with soda-piperidine treatment have been studied to clarify the acceleration mechanism of delignification with piperidine. Based on these results, the effect of amine on delignification during soda cooking has been summarized as shown in Fig. 1 of this paper. This shows that various nucleophilic amines react with the electrophilic reactive site of lignin, and therewith accelerates delignification by preventing the condensation reactions of lignin molecules.In this paper, thirteen kinds of amines were selected, and their delignifications with anthraquinone additive (AQ) were compared by the use of red pine and birch wood meals. Furthermore, mixed chips (spruce and abies) and red alder chips were cooked with sodamethylamine and -dimethylamin, and the pulp properties were compared with those of kraft cooked pulp. The results are summarized as follows : (1) Red pine and birch wood meals were cooked with thirteen kinds of amines. Delignification of birch is accelerated with amine, but that of red pine is not enough within the cooking conditions used here. Nucleophilicity of amino group affected by alkyl group is not so strong, and the steric structure and solubility of amine in cooking liquor will also affect the delignification.(2) The delignification by soda-amine cooking is accelerated with AQ additive. Amine alone, however, may not be enough as cooking additive, contrary to our expectation.(3) Sheet strength of cooked pulp with amine and AQ additives is stronger than that with amine alone. Soda cooked pulp with dimethylamine and AQ additives (0.2% amine and 0.05% AQ on chips) shows the similar sheet strength to kraft pulp, especially in the case of red alder.

Concerning pulp production from non-woody plants, we have been studying on the chemical pulping of rice and wheat straws since 1987. There are two reasons why this research project was planned. (a) More than 99% of pulp are produced from wood in Japan. Considering the increase of paper demands in future, it is doubtful whether or not we are able to obtain enough materials in future, and we may be obliged to use non-woody plants even in a small amount. For information, kenaf, non-woody plant is noticed recently as pulp materials. (b) China is well-known country to use non-woody plants like straw, reed, bamboo and so on as pulp materials. Soda cooking has been mainly adopted in the case of pulp making. However, the recovery of soda and the utilization of dissolved lignin in black liquor are not developed yet. This is due to a large quantity of ash which disturbs the post-treatment of black liquor. On the basis of two reasons above-mentioned, it is necessary for Japan to adjust the pulping process of non-woody plants seems to be appropriate at the present technical level. Moreover, the removal of ash from black liquor and the utilization of lignin are also indispensable to be solved.This report describes the pulp analysis and the pulp sheet strength of rice and wheat straws by soda and alkaline sulfite cookings. Moreover, soda lignin was isolated from black liquor and sulfomethylated, and the dispersion property of sulfomethylated lignin was examined. The results are summarized as follows : (1) Delignification of rice straw by soda cooking is more rapid than that of wheat straw. Corresponding with delignification, the brightness of the former is higher than that of the latter.(2) The ash fraction is dissolved during soda cooking, although a few % of ash is still contained in soda pulp. However, the ash fraction during alkaline sulfite pulping is difficult to be dissolved, and 1617% of ash are contained in pulp. Such a high amount of ash may regulate the extensive application of alkaline sulfite pulp.(3) Sheet strength of soda pulp is higher than that of alkaline sulfite pulp. However, these strength results represent only the preliminary work, because there is the difference of about 100 ml CSF between soda and alkaline sulfite pulps.(4) Standard dispersing number of sulfomethylated lignin is higher in rice straw than in wheat straw.(5) Summarizing the previous (2) - (3) items, soda pulp is superior than alkaline sulfite pulp.

The amount of the diarylpropane type structure in spruce lignin was determined by the use of an ozonation method. Ozonation of both the diarylpropane and the phenylcoumaran type structures resulted in the formation of a dicarboxylic acid which possesses the original configurative structure of the side-chain. By determining yields and ratios of erythro and threo isomers of this dicarboxylic acid formed from model compounds and MWL, it was elucidated that the diarylpropane type structure can not be one of the major structures in spruce lignin

A new cooking process with sodium sulfite, formaldehyde, and a quinone compound (1, 4-dihydro-9, 10-dihydroxyanthracene sodium salt: DDA) was devised in order to produce soft wood semichemical and chemical pulps which are superior to neutral sulfite and kraft pulps, respectively. In this studies, this process was evaluated in terms of the optimum compositions of cooking liqnor, delignification selectivity, and pulp qualities.The results were as follows:(1) The addition of formaldehyde to a sodium sulfite-DDA solution accelerates delignification of yezo spruce. The optimum molar ratio of formaldehyde to sodium sulfite for delignification is in the range of 0.15-0.70.(2) Delignification selectivity in sodium sulfite-formaldehyde-DDA cooking is better than that in neutral (weakly alkaline) sulfite-DDA cooking. Lignin-free yields by the former cooking are 2-5% higher than those by the latter at a given delignification.(3) Delignification rate of yezo spruce in this cooking is comparable to that in kraft-DDA cooking, when the dose of DDA is increased to 0.5% on o.d. wood. Lignin-free yields by the former are 9-10% higher than those by the latter at a given delignification.(4) Yezo spruce/saghalien fir pulp produced by this cooking has higher tensile and burst indices, and higher brightness than kraft-DDA pulp.

AbstractGlycidyl celluloses were prepared from completely allylated methylcellulose and tri‐O‐allylcellulose with m‐chloroperbenzoic acid in homogeneous chloroform solutions. The degrees of substitution (DS) by epoxy groups were 0.60 and 1.33 for the products prepared from allylated methylcellulose and tri‐O‐allylcellulose, respectively. They were soluble in not only many organic solvents, but also methanol‐water mixtures [more than 70% (v/v)]. These products were characterized by infrared spectroscopy (IR), 13C‐NMR spectroscopy, and gel permeation chromatography (GPC).

Tri-O-benzylcellulose was oxidized to benzoylcellulose in good yields by ozonization. Degrees of substitution (DS) of benzoylcellulose thus prepared were higher than 2.5. A little depolymerization during the ozonization of tri-O-benzylcellulose was detected by gel permeation chromatography. In contrast, tri-O-p-methoxybenzylcellulose gave other reaction products than p-methoxybenzoylcellulose.

Etude de la quantite et de la structure des carbohydrates et de la lignine dans trois echantillons de bois enterres dans un depot de tourbe: Fraxinus vieux de 12000 ans, Torreya vieux de 6000 ans, Castanea, vieux de 6000 ans. Comparaison avec le bois d'arbres vivants des memes especes

The delignification rate constants were calculated as observed (pseudo) first-order reactions, and the effects of [OH-] and [SO32-] on the rate constants were evaluated in the Salkaline sulfite cooking with and without DDA (1, 4-dihydro-9, 10-dihydroxy-anthracene sodium salt). The delignification rates were also compared with those for kraft and kraft-DDA cookings.In the alkaline sulfite-DDA cooking of spruce and beech wood meals under the same conditions, the delignification rate constants for beech were not necessarily higher than those for spruce wood meals. This is quite different from the general observation for the soda, soda-DDA, kraft, kraft-DDA cookings, in which beech is higher than spruce. Especially in the case of beech, the delignification was not accelerated when the sodium sulfite concentration was increased from 0.4 M to 0.8 M. The addition of DDA could increase the effect of [32-] on the delignification in the alkaline sulfite cooking while it was not the case for [SH-] in the kraft cooking. Total alkali charge was higher in the alkaline sulfite-DDA cooking than those in the soda-DDA, kraft, kraft-DDA cookings to have a given rate constant.

Cellulose ethers having various amounts of carbon—carbon double bonds were prepared by allylation or methallylation of commercial methylcellulose (DS = 1.6). Namely, methylcellulose dissolved in dimethylsulfoxide (DMSO) was treated with allyl chloride or methallyl chloride in the presence of powdered sodium hydroxide as a base. Tri-O-allyl and tri-O-methallyl celluloses were also prepared easily from commercial cellulose acetate (DS = 1.75) with powdered sodium hydroxide and the corresponding chlorides. Thermal stabilities of these cellulose derivatives and their behaviors to oxygen in the air were studied by the use of TG-DSC and solubility test, respectively.